FAI fuel
 

Is there a glow engine that you can buy in the US that will run correctly on 0% nitro? I was told that the engines that you can buy in say the UK are set up to run on 0% because the US is the only country that makes nitro.

RE: FAI fuel
 

Just straight methanol and castor oil does not run as good as we are used to with our model engines in the USA.

Typically the needle valve is difficult to adjust. one click will be the difference between too rich or too lean

The solution is to use 3-5% Acetone in the FAI type mixture

You can also just buy 5% nitro fuel

Anymore we are also not accustomed to all castor oil for lubrication. Most of use are used to a 80% synthetic and 20% castor oil ratio for the lubrication package.

RE: FAI fuel
 

Many countries produces Nitro, but it is usually cheaper in the USA.
here in Germany you can get also nitromethane, but it cost about 20EU a liter....

I would say most sport engines like O.S and similar will run O.K with no nitro, maybe you won't get every bit of maximum power, but they will run fine.

I run an o.s 46 fx, magnum xls 46 and tower 75 with no nitro and no problems, they run fine and reliable.

I'm living in germany since last year, and I've run here only a 4 stroke engine, with nitro, so I don't know how it runs with no nitro.

saludos,

Jorge

RE: FAI fuel
 

With the proper adjustment of the compression ratio, most engines will run almost as well with no nitro as they do with it.

RE: FAI fuel
 

As a point of clarification, "FAI Fuel" is 80% methanol and 20% castor. Notice there in no provision for nitro but also no allowance for synthetic oil. The term "FAI fuel" is often used to simply mean no nitro fuel and while that is correct, FAI fuel really is 80% Methanol - 20% Castor... no exceptions. This is per the FAI sporting code. It must be 20% oil and all 1st pressing castor.

In general, this is not a good modern fuel blend. Even EU engines set up to run on low/no nitro do not need 20% oil and no modern engine needs an all castor fuel package. Modern competition engines optimized for classic FAI fuel do run well but are not easy to set up and tune and, in general, would be better off with at least some nitro and far less castor.

While it is usually cheaper in the US, most of the nitro the US uses come from China. To the best of my knowledge only the US and China produce Nitromethane.


Cheers,



Bill

RE: FAI fuel
 

Agreed; if the metallurgy/design is so outdated that 1/5 castor oil is required to keep the thing alive, I'd want to see if I had suffered a time warp anomaly and accidentally bought it 40 years ago then returned in a puff of smoke. It has been said many times that I can recall by assorted engine columnists and others, that current engines designed for no nitro fuel respond very favorably to current syn/cas fuels and that the idle and throttle response are noticably improved on 5% nitro. My own observati0ons agree so far.

As to the OP's question, certainly you can buy engines over here that will run well on these blends - MVVS, Rossi are two names that comes to mind. If the engine has head shims installed you can always bump compression if it seems necessary. Or, run the engines you are used to on 5% fuel or FAI fuel and see how things go. Many folks do and are happy. Is it your goal to use FAI fuel, or are you just curious?

MJD

RE: FAI fuel
 

My Moki 1.8 and 2.10 loved Morgan FAI fuel.

RE: FAI fuel
 

Normally the engines that run with low(5% max)/no nitro are (from what is usually said here)

MVVS
Webra
Super Tigre
Moki
Laser
Rossi
MDS

Do you see something in common there?

At home (Colombia) for me no nitro fuel was the choice between flying and staying at home...I had to pay too much for a gallon of fuel, where I could mix my own about the 20% of the cost. The same for the oil....there I can only get castor, eventually I could see klotz at the hoby shop, but it costed too much to make it usable for me... we have a problem there...and is the dollar course....it is about 2000 pesos to 1 dollar...and in Colombia you buy a coke with 1 dollar...we buy it with 1000 pesos....just like here in Germany, a coke is about 1EU [:'(], so in my country you just have to pay about the double of the price plus what the poor owner of the LHS earns...


About the countries that produce Nitromethane....I really don't know, I guess I meant that nitro is available in many countries.... not quite easy thought.


Saludos,

Jorge

RE: FAI fuel
 

Super Tigre!

jack

RE: FAI fuel
 

Castor still provides the best protection against lean runs, but it doesn't take all castor to do the job. You also get rust protection with it.

Nitro is also made in large quantities in India.

The price of nitro in most European countries is mostly a tax driven issue. We have the same tax increased prices on other hobby items here, but fortunately not nitro.

RE: FAI fuel
 

Why I asked the question is that I mix my own fuel and I was going to give FAI a try, that is with 20% castor oil. I have some new ST ABC engines that are 20+ years old that I would run on it.

RE: FAI fuel
 

Is the Morgan FAI fuel you talk about 20% Castor oil? Thanks capt,n

RE: FAI fuel
 

Ihave found most engines in my collection will run OK on FAI fuel. If Isimply increase the compression a little. And use a hot plug. Merlins work great.

RE: FAI fuel
 

Morgan doesn't have a clue what real FAI fuel is but that goes for most American fuel manufacturers where it's just become a generic term for any fuel with zero nitro. There's a reason why FAI fuel is 80/20 methanol/castor. To keep a level playing field in events where power is an absolute requirement (CL speed, RC Pylon. FF power) the only fuel allowed is methanol, no spiking with nitro or any other additive that can burn and possibly add to the power output. Castor was chosen as the oil because it doesn't burn and is well known for its lubricating ability under extreme conditions. Also it's cheap and readily available.

Engines available in the UK are exactly the same as similar engines available in the USA (OS, Enya, ST, you name it) and they'll all run perfectly well with zero nitro. As a for instance, my old (second hand) ST GS45 ABC with its low compression of 8.5:1 turns an APC 10x6 at 14,600 on 75/25 castor so it's no slouch and tuning is dead easy.

RE: FAI fuel
 

Add Enya engines to the list, my SS30 c/l loves FAI as does my 46-4C in fact when use a synth blended lube my Enya's generaly lose 300 RPM here's a vid of the 46 with one head shim 12x6 mas on FAI...

[youtube]http://www.youtube.com/watch?v=O6q358B260I[/youtube]

RE: FAI fuel
 

Luna,
You sure could here the rpm drop when you disconnected the glow power though. The idle did not seem very stable.:eek: I am looking for performance that does not sacrifice the ability to idle. I have two early era race planes, and a reliable idle is important enorder for you to land them.;)

RE: FAI fuel
 

All true... but I'll add... FAI fuel, as described by the sporting code, has not changed in the 40 plus years that I've been modeling and I believe it was "created" decades before that. Taken in the context of the time true FAI fuel was defined, it makes more since. At the time of "FAI fuel's" creation, "glow" engines were relatively new, fuel additives included many that were very dangerous, liners were steel, piston were iron, and the only oil KNOWN to keep engines running over time was castor. At the creation of FAI fuel, model Schnuerle engines didn't exist. Neither did ABC/ABN/AAC engines. Synthetic oils were potentially faster but poor lubricants, and the sky was the limit for additives. Nitro was one of them but others existed that were explosive or carcinogenic or both.

Fast forward to todays world of comparitably readily available Nitromethane, the invention of (good) synthetic oil, and chromed brass or aluminium liners with very high silicone/low expansion pistons and the best reason for continuing to use FAI fuel is that it allows you to compare model performance over time. Yes, prohibiting the use of nitro reduces cost considerably for most/all modelers but that doesn't explain the requirement for 20% all castor oil.

Bill

RE: FAI fuel
 

You are kidding right?

The engine was stone cold, 2 flips and it starts right up and 5 seconds later the glow driver was removed, I wonder why it stumbled gee let me think....

RE: FAI fuel
 

In the competition arena cost doesn't play any part but standardisation of fuel components does. Sure, the rules could be changed to say that FAI fuel will be 83% methanol and 17% Klotz oil but what if Klotz change their formula or go out of business? Castor has been and always will be simply castor. Some people will try to push the rules to the limit to gain the slightest edge over their competitors and if they could find a synthetic that would not only lubricate but also have a powerful burnable component then they'd use it, even if it cost $100 a quart. Under FAI rules (for the 3 events that require it) you can use your own fuel to practise and find the best tune but in any competition flight the organisers supply the fuel.

As you said, the best (and only) reason for using FAI fuel is to compare performance over time. That's the level playing field thing again.

RE: FAI fuel
 

It should not drop rpm like that when pulling the glow power cold or hot. Maybe I am just to used to my YS 1.10's 2000 rpm. Even my Tower .75's on 10% do not drop like that, and I do not even let the glow power on 5 seconds. The needing to clean out is normal though.

RE: FAI fuel
 

The idle is fine on the enya once it has warmed up I wonder why you failed to notice that?

RE: FAI fuel
 

Also bear in mind that most 2 stroke model aero engines are "designed for sale in the USA" - by that I mean that the compression ratio is on the low side 'coz the manufacturers know that most (USA) people will run a nitro based fuel.

Therefore, to run a 2 stroke engine on zero nitro fuel, a quick & often very effective solution is to remove the head & take out one or both of the head shims, thereby increasing compression. Take the usual care of course to ensure the plug does not come into contact with the piston plus ensure correct prop selection.......and off you go.

RE: FAI fuel
 

Also note too, that most carbies are designed for nitro fuel, that's why the transition can be less smooth than it should when running nil nitro. If you’re handy you can re-profile the low speed needle, and the transition will come back.

mike.

RE: FAI fuel
 

I used 80/20 for many years.
Ran OS, Enya, Webra, HP and HB.
They worked... but thinking back, they where a great deal more finicky than today.
Mind you, my Moki runs just perfect.

Apart from the YS engines (and the Moki), I've dropped the oil content down to 15% on everthing else.
Perfect.

RE: FAI fuel
 

I've been running fai for the first time this season on my moki and give some of the following comments.

1.How come its working without Nitro? Its a myth all engines need nitro.
2.ok you need an engine with high compression and moki sure are that.
3.The cost!! I pay about£8.50 a uk gallon and petrol is over £5 a gallon, so only slighlt more than gas and MORE power,less weight,ok bigger tank but its light when you land
4.The nitro costs,say for good 16 sythn fuel costs about £22 so BIG glows that need nitro could hurt the wallet.
5. The smell is lovely.!! Castor has a nice whiff compared to sythns
6. Castor residue sucks, but extentending the exhausts furher, makes for a cleaner model and meths/water is a great cheap cleaner.
7.The exhaust will go black, but if its hidden in the cowl,it doesn't matter.
8.leaner runs with all that castor.!! More power
9.Once you know how to set a needle,you don't need the nitro to help you. My tolerance is half a turn,too lean-rich
10.Other engines have you by the balls,once they comit you to nitro

I think the comment about fai fuel being a test over a period of time rings true

RE: FAI fuel
 

While many engines will run fine on FAI fuel I STONGLY recommend that 20% castor fuel NOT be used on four stroke engines.

I've spent hundreds and hundreds of hours working on different fuels and running model engines and one of the challenges is finding a fuel that not only runs well, but runs well for many, many hours. It's one thing to get an engine to fire up and run for a few tanks and quite another to get one to run for 100 hours. Castor in four strokes is a good example. If brownish deposit form on the comparatively warmish outside of the muffler, you should see the exhaust valve stem of some of the 4C engines I've seen run on high castor fuels. What is a brown spot on the outside of an engine muffler becomes a black rock on something as hot as the exhaust valve.

A few year back I had a friend ask me to look at an engine that he believed had broken a ring or was just worn out. It had NO compression. After removing the exhaust header the reason for the problem became clear. It looked like someone had stuffed and Oreo cookie in the exhaust plenum! There was so much charcoal on the exhaust valve it couldn't close! I ended up taking about a 3 carat rock of carbon out of an OS .91. After de-coaling, it ran fine.

It would also be a disservice to not point out that many early 4C engines were NOT tolerant of much nitro and had a propensity to throw props when run lean. I don't know exactly when the Enya .46 was produced but I don't see it in the current Enya catalog suggesting it is a little bit older. The fact that this engine runs OK on no nitro fuel may or may not mean it's a good fuel for newer engines. New OS and Saito engine respond very well to Nitro. That isn't to say they NEED nitro... only that they run better with nitro... (and a little Propylene Oxide!)

For those following this thread, it may be unwise to look at a short video of a 4C engine running on FAI fuel and decide that it would be a good idea for them to do the same.

Bill

RE: FAI fuel
 

You can run a castor/synthetic blend in those STs. I hve some STs that old that hafe run fine on a blend of oils.

CR

RE: FAI fuel
 

I agree on the de-coking. A friend once showed me a OS .48 Surpass that ran but at low power output. The exhaust port was colgged with gummy milk-chocolate colored residue. After I cleaned that out it ran fine. He had always run it on 10% nitro - 20% castor. After he switched to a castor/synthetic blend it was OK.

CR

RE: FAI fuel
 

No questions about it... Modern engines run better on modern fuels.
The exception being a Moki.
I wouldn't concider running castor on any of my engines anymore.
As stated 15% synthetic works brilliantly for me.

RE: FAI fuel
 

Charley, it sounds to me like it was okay running with 20% castor oil. You just needed to clean it out periodically. This isn't uncommon with larger gas/petrol powered two-strokes either. It's just part of the process of owning and running a two-stroke engine.

Only in model airplanes do I see this obsession for running oils that leave the engines spotlessly clean internally. I haven't seen any kind of proof certifying that cleaner engines last longer than carboned up engines that are cleaned periodically. I'd rather add coke than remove metal to my engines during their operation, if you catch my drift.

Come on oil manufacturers, give us your best shot and present some data proving your side of the argument.


Ed Cregger

RE: FAI fuel
 

I have somewhere around 30 four strokes and the exhaust valve stems get black but I've never seen any clumps of carbon in them

I have always run the 80-20 and 75-25 synthetic-castor mixes at the 16-18% total oil levels

RE: FAI fuel
 

David, what would you run in a Moki?:eek: Mine is a new 1.35[:-] ....may need to sell it..._hit[&o] Capt,n

RE: FAI fuel
 

The straight 80/20 Castor. Have also used 5%, couldnt tell the difference (i't must do something) so if it's there I'll use it.
Have also used a Synth/castor mix... worked fine.
More Nitro just doesn't work at all.
I have a 1.35. It's very OK. They need some serious running in though. And is you don't follow the book, you can screw up the nice new engine.

RE: FAI fuel
 

W8ye,
I allways run a little caster in fourstrokes except for YS. Castor in a YS is asking for problems. Not only the gumming up of the regulator, but mainly the exhaust valve that will get deposits and then stick. Its very expensive to fix then.[X(] Do to the path the fuel takes in a YS fourstroke, the bearings are much better taken care of.;)

RE: FAI fuel
 

There is another problem...I cannot find the BOOK to it! Capt,n

RE: FAI fuel
 

80/20 castor.
Old school bench run.
Nice and rich. Short prtiods.
Run one min'. Stop engine, let it completely cool down before restarting Do this x 2
Run 3min' Stop engine, let it completely cool down before restarting, do this 5 times.
Run 6 mins, Stop engine, let it completely cool down before restarting. Do this x3 and occasionally lean it briefly out by squeezing the fuel line.
What you are looking for is a decent 30-45 min (running) breaking period consisting of short runs, cooling down periods.
It's takes some hours!
After that try some extended runs for a couple of tank fulls, rich from peak and peaking it out for some seconds.
Then it's pretty well run as usually without really looking for max power etc.
It takes several gallons before it's really happy.
Take your time and you'll be rewarded.

RE: FAI fuel
 

And PS.
Do the above at full throttle(super rich) and not at idle.
Don't bother touching or even trying to dial in the idle until you gone through the above.
As stated, old school approach. It takes time.

RE: FAI fuel
 

Would a mix of 80% alky /10% synthetic / 10% Castor work OK if I run it easy? Thanks, Capt,n[X(] Did edit..forgot the % symbols!!!:)

RE: FAI fuel
 

I'd do the initial "voodoo" with straight castor.
There are some very strange "metal-science-thingies" taking place during the initial runs.
Best understood by Hungarian PhD's, used to Cold War budgets.[8D]
20% Castor is part of alchemy.

After the breaking ritual one is more free to mix the oil and add 5% frogs leg to the brew.
But the longer you leave it the better.
I'b bet you're looking at least 10 gallons before the engines considered ripe.

And prop: 16x10 absolutely the best I've tried.
For everything.

RE: FAI fuel
 

Hi!
Agree with you Motorman...A typical four stroke running on no nitro!
High idle (To high for me) ! 2000 rpm is more in line with my preferences.
And not that good throttle respons! I want Instant response!
You only get this with a little nitro (5%)